Used as portable storage. Excellent speeds. Can maintain ~120MB/s sequential writes with large files (from an internal SSD). So good in fact, most of the old 3.5" internal drives in my desktop cannot keep up! Keep this in mind when deciding whether an upgrade to an SSD portable is worth it i.e. if not from SSD to SSD, don't bother paying the premium.
It was used to plug into Xbox as a means of transferring games from one to another / extra hard drive space. Once plugged in, xbox formatted the drive for us. Had a 45gb file transferred in approx 12 minutes. Also plays straight from the EHD itself. Works perfectly for our needs - will probably get a 2nd one.